Aging and Disease Course: Contributions to Lifespan Neurobiology of Schizophrenia

The 2020 NIMH Strategic Plan for Research calls for investigations targeting neurobiology of mental illness across the lifespan. Growing evidence suggests that lifespan neurobiology of schizophrenia (SZ) incorporates two distinct dimensions: aging and disease course. However, their clinical correlates, associated biomarker trajectories, and implications for treatment are unknown. This study will investigate differential aspects of SZ neurobiology captured by aging and disease course, in order to develop specific biomarkers which may offer actionable targets for SZ stage-dependent intervention. The study is predicated on a novel mechanistic Model of SZ Trajectories across the Adult Lifespan, positing distinct biological fingerprints within the anterior limbic system for aging and disease course in SZ: (1) alterations in the circuit's function and structure that occur earlier in the lifespan and are larger in magnitude than the alterations expected with normal aging (accelerated aging dimension); and (2) regionally-specific anterior limbic "hyperactivity" in early SZ, with a subsequent transformation into "hypoactivity" in advanced SZ (disease course dimension). In a sample of SZ and matched healthy controls (n=168, 84/group) aged 18-75 years the investigators will ascertain a broad panel of biomarkers \[via multimodal brain imaging: optimized 1H-MRS, high-resolution task-based fMRI, perfusion (Vascular Space Occupancy) and structural MRI\], along with comprehensive cognitive and clinical assessments. All measures will be acquired at baseline and repeated at 2-year longitudinal follow-up. Using cutting-edge computational approaches, the study will examine (i) effects of aging and SZ course on anterior limbic system biomarkers; (ii) lifespan trajectories for different biomarkers; (iii) patterns of limbic system biomarkers in age- and SZ course-based subgroups (e.g., Younger vs. Older, Early-Course vs. Advanced SZ), as well as in data-driven subgroups (e.g., those with vs. without accelerated aging profiles); and (iv) associations between biomarkers and cognitive and clinical outcomes. This research will advance the field by providing novel biomarkers that capture unique neurobiological contributions of aging and disease course in SZ, and will motivate future studies on SZ mechanisms across the lifespan and development of precision treatments.